Hi, @KhoaND
Has this email address (or alias) ever been removed from your Microsoft account before?
Also, may I know when was the last time you were able to access that Microsoft account?
I ask because Microsoft may permanently close accounts that haven’t been used for over 2 years. Microsoft’s account activity policy is here: https://support.microsoft.com/accounts-billing/manage/microsoft-account-activity-policy
Also, please try searching for the account using these steps from Microsoft: https://support.microsoft.com/account-billing/forgotten-your-microsoft-account-username-b2049472-3b8f-27d3-61c6-67a668453f4c Click on "Search" and follow the instructions provided.
If you receive any error messages, such as “account doesn’t exist” or anything else, please let me know.
Thanks!